You've probably never thought of the saliva swishing around in your mouth as amazing. The fact is, though, life would be a lot harder without it. Digestion would be quite unpleasant without its enzymes breaking down food during chewing; the soft tissues of our mouth would suffer more environmental abuse without its protective wash; and without its ability to neutralize acid, our tooth enamel would erode.

What's also amazing is what saliva can reveal about our health. As researchers discover more about this phenomenon, it's leading to better and less invasive ways to diagnose disease.

Similar to blood, saliva is composed of proteins containing RNA and DNA molecules which together hold the genetic instructions the human body needs to reproduce cells. We can therefore test saliva for health conditions as we do with blood, but with less invasive collection techniques and far less hazard to healthcare workers from blood-borne diseases. For example, doctors now have a saliva test that can detect the presence of HIV viruses that cause Acquired Immune Deficiency Syndrome (AIDS). Another saliva test will soon be available that can test for hepatitis.

Unfortunately, only a few such tests now exist. Researchers must first identify and then catalog saliva's biomarkers, protein molecules that correspond to specific health conditions — a daunting task since most are marked not by one but hundreds of proteins. Then it's a matter of developing diagnostic devices that can detect these biomarkers.

Although that too is a huge task, existing technology like mass spectrometry (already used to help detect early stages of oral cancer) could be a promising starting point. This process measures the portion of the light spectrum emitted by a molecule, a feature that could help identify a saliva protein by its emitted light signature.

Thanks to the work of these researchers, many of them in the dental profession, information about our bodies contained in saliva may soon be accessible. That accessibility may lead to earlier diagnoses and more successful treatment outcomes.